Field of the Invention
This invention relates to a system for the cushioned support of electronic components as conceptually specified in claim 1, and to a method for producing such integrated, cushioned support mounts by means of said system.
The object of this invention is a structure for supporting electro-acoustic transducers and other electronic components in miniaturized devices such as hearing aids. Electronic components such as hearing-aid receivers or electro-acoustic transducers are most commonly held in place by means of rubber mounts. In most cases these rubber mounts are plugged, glued or slipped directly onto the electronic component, defining the area of contact with the remainder of the electronic miniature device such as the architecture of a hearing aid. In addition to the individual supports it is usually necessary to also accommodate leads and for instance a sound conductor that connects the component to the acoustic surroundings and often serves as a mechanical support as well.
These traditional rubber mounts serve three functions:                they hold the electronic component in its intended position within the miniature device, for instance a transducer in a hearing aid;        they isolate the component from its mechanical surroundings, absorbing vibrations; and        they protect the electronic component against percussive impact.        
Description of Related Art
Existing literature describes various approaches to obtaining a cushioned support for electronic components as outlined above, for instance for the mounting of transducers and in particular receivers (speakers) in hearing aids. For example, EP 1 248 496 describes a multi-part receiver support that is adapted to the force distribution pattern on the receiver surface by means of rubber segments featuring different degrees of rigidity. U.S. Pat. No. 4,729,451 describes an integrated mount for the receiver of an in-ear hearing aid. A receiver mock-up is placed in a single shell and the tip of the shell is filled with a liquefied rubber material. After the curing the mock-up is removed, leaving behind an integral cavity that then serves as the receiver mount.
U.S. Pat. No. 6,751,326 describes a support concept whereby a receiver is mounted in a two-part enclosure. The rubber parts are mounted on the receiver and/or on the enclosure.
WO 2005/055652 describes a receiver mount in a hearing aid which mount is held in place by means of multiple rubber parts that must be attached to the receiver as well as to certain segments of the enclosure.
EP 1 316 239 includes a general description and a few application examples for employing multi-component injection molding techniques in producing hearing aids. These involve enclosure seals, sound channels for sound entry and exit, and an elastic mounting cavity for transducers.
Finally, WO 00/79835 addresses a behind-the-ear hearing aid that incorporates an electroacoustic transducer with a speaker enclosure that is resiliently mounted in a capsule in such fashion that a space is defined between the capsule and the speaker enclosure.
The drawbacks of these prior-art support mounts include, in particular, the following:                The rubber parts concerned are relatively expensive to produce and, in view of the small amount of vulcanized material, consistent material properties (rigidity, damping performance) are not always assured.        Attaching the partly very thin-walled rubber mounts on the transducers is extremely complicated. For one thing, it is very time-consuming in the production process and, for another, the acoustic reliability of the hearing aid depends in large measure on precise assembly. A slight deviation or shift of the rubber parts can skew the transducer in the hearing aid enclosure, leading to acoustic feedback.        Most prior-art support mounts do not permit any separation between shock absorption and vibration isolation since both functions must be performed by the same component, consisting of the same material.        
Of course, there are approaches that are less demanding on the mounting of transducers. In one, the transducer is made more insensitive to percussive shocks, as described for instance in EP 0 993 759. Moreover, transducer manufacturers have made efforts aimed at lowering receiver vibration, as described for instance in EP 1 248 496, in U.S. Pat. No. 6,751,326 or in EP 127 442. These approaches are all going in the right direction but may in certain cases prove to be unsuitable for a particular use in hearing aids because they increase the cost and/or size of the transducer.